Method and apparatus for bonding using brazing material

ABSTRACT

A method and apparatus for bonding components with a brazing material is described in which atmospheric plasma with active species is created by gas discharge generated in a gas capable of discharge at or about atmospheric pressure, and a portion of a component is exposed to the atmospheric plasma, thereby surface treating it. Prior to, simultaneously with, or following the surface treatment, bonding is accomplished with a brazing material. Surface treating the portion of the component allows using solder and, for example, a low-corrosive or no-rinse flux, or no flux, in an efficient bonding process. Furthermore, unwanted organic substances, for example, left over flux, may be removed by exposing the component to surface treatment, for example, after bonding is completed, or, if the component has residual undesirable organic substances, for example, left over from its manufacture, surface treatment may be performed prior to bonding.

This is a continuation application of application Ser. No. 08/512,740,filed on Aug. 8, 1998 now U.S. Pat No. 5,831,238, which is acontinuation in part of PCT/JP94/00573 filed Apr. 6, 1994.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of International ApplicationPCT/JP94/00573, with an international filing date of Apr. 6, 1994, nowpending, entitled "Method and Apparatus for Bonding Using BrazingMaterial," by inventors Miyakawa Takuya, Mori Yoshiaki, Kurashima Yoheiand Anan Makoto. This application is incorporated herein by reference asthough fully set forth.

BACKGROUND OF THE INVENTION

1. Field of Technology

This invention relates generally to a soldering method and apparatusthat uses a brazing material to bond components together, and moreparticularly to a soldering method and an apparatus which may besuitable for use in soldering applications performed in small areas orrequiring fine detailed work, such as in bonding electronic componentsto a printed circuit board.

2. Background of Technology

Traditionally, the soldering methods most suitable for industrial massproduction have been the flow method and the reflow method. For example,the flow method is often used for mounting components onto a printedcircuit board or other workpiece (hereinafter referred to generally as"substrate"). In the flow method, a substrate on which electrical orother components have been placed is coated with flux, and thensoldering is achieved by passing the substrate, components and fluxthrough a molten solder bath thus soldering the components to thesubstrate.

In the reflow soldering method, a mixture of flux and soldering paste isapplied, or printed onto that part of the substrate on which theelectrical or other components are to be soldered. Then, the componentsare placed on the substrate over this flux and solder paste layer andsoldering is achieved by passing the substrate and components through aheating oven, otherwise known as a "reflow oven" thus soldering thecomponents to the substrate.

However, it is often difficult to consistently and uniformly produce aneven coating of flux on the bonding portions of the substrate. This istrue whether the flux coating is applied over components, as in the flowmethod, or directly onto the substrate, as in the reflow method. Forthis reason, the coating step has become a major obstacle to achievingautomation in semiconductor manufacture as substrate patterns havebecome finer and the density of electrical or other components hasincreased. Furthermore, in both methods, residual flux on the substratemay be corrosive or otherwise detrimental to the electrical or othercomponents, and thus, it is usually necessary to rinse and clean thesubstrate after soldering has been completed, thereby requiring yetanother process step. Additionally, when soldering a TAB substrate to aliquid crystal panel, for example, there is the potential problem thatthe soldering flux may splash and contaminate the polarizing film.Consequently, it is usually necessary to attach a protective film to thepolarizing film before soldering, and then to remove this film after thesoldering is finished. These additional process steps increase the totalnumber of process steps, time, and labor, resulting in increasedmanufacturing costs and lower manufacturing efficiency.

Known methods of removing or otherwise cleaning organic substances, suchas flux from a substrate include the wet rinse method which uses anorganic solvent to remove organic substances such as flux, and the dryrinse method, which removes organic substances such as flux by causingdecomposition by chemical reaction, for example by irradiation withozone, and/or ultraviolet light.

However, the wet rinse method requires an additional cleaning processfor removing the rinsing agent after the organic substances have beenrinsed off, a process for drying the substrate, and a facility forperforming these processes. These additional process step requirementsfor the wet rinse method necessitate a massive amount of time and laborand typically result in increased manufacturing costs and loweredoverall efficiency.

On the other hand, thorough cleaning of organic substances cannot alwaysbe expected using the dry rinse method since it is difficult tocompletely remove certain organic substances, especially thosepossessing, for example, especially large molecular weight.

To avoid the problems of conventionally used rinse methods, no-rinsefluxes containing very little or no activators, for example, chlorine,have been in use recently. However, because these fluxes possess poorwettability compared with conventional fluxes, the use of these no-rinsefluxes raises the potential that the resulting bond may be incomplete ormay have insufficient bonding strength to be used reliably for joiningthe components to a substrate.

Furthermore, when components must be soldered on both sides of asubstrate, the heat treatment applied during the soldering of componentson one side often causes the formation of an oxide film, for example,CuO on the surface of the copper pads and electrodes. The heating alsomay cause the loss of even the initial level of wettability on the sidestill to be bonded. In some cases, the heat treatment even leads toincreased contact resistance during soldering.

Unexamined Japanese patent application No. H03-174972 discusses a methodwhich obtains excellent adhesion of a soldering material to a substrate.In this method, the substrate bonding surface is exposed to argon plasmagenerated in a low pressure argon gas atmosphere by an electricaldischarge. This argon plasma generated by electrical discharge is usedto remove impurities from the bonding surface of the substrate and toimprove its wettability. Then the substrate is coated with the solderingmaterial.

However, this method necessarily requires a vacuum pump and a vacuumchamber for obtaining the low pressure argon gas atmosphere, making theoverall processing apparatus large and complicated. Furthermore, argon,the gas used for generating electrical discharge, does improve thewettability between the soldering paste and the substrate, thusimproving the printability of the paste solder, however, it does notimprove the wettability of the solder itself for the components since itdoes not remove the oxide film. Therefore, using this method, it isstill necessary to coat the soldering surface with a flux in order toremove the oxide film before soldering, and consequently, this flux mustbe rinsed off after the soldering process is completed.

Furthermore, unexamined Japanese patent application No. S3-127965discusses an apparatus that is equipped with a device which generates anarc discharge between itself and the components to be soldered, and thusquickly heats the components. This device makes it easy to solder acomponent, even if its heat capacity is excessively large. However, withthis device, the electrical discharge is used to generate the heatrequired for soldering, and cannot be used to remove an oxide film orimprove the wettability. Furthermore, since the gas used for generatingthe discharge is an inert gas, removal of the oxide film would not beexpected to occur in theory. This method also requires that thesoldering surface be coated with a flux in order to remove the oxidefilm, necessitating that the flux must then be rinsed off aftersoldering. Thus, additional process steps are required which lower theefficiency and raise the costs of the overall manufacturing process.

Accordingly, it is desired to provide an improved method and apparatusfor bonding using brazing material.

SUMMARY OF THE INVENTION

Generally speaking, the present invention provides a method andapparatus for bonding that uses a brazing material to bond twocomponents into one, in which at least one step or part includesgenerating a gas discharge in a gas capable of discharge at or aboutatmospheric pressure; and in that the method and apparatus includes asurface treatment which exposes the surface of at least one of thecomponents to atmospheric plasma containing active species and excitedgas molecules or ions generated in the gas by the electrical discharge.An excellent bond can be obtained by applying such a surface treatmentat least before, during, or after the bonding of the two components.

Furthermore, when solder is used as the brazing material, the inventionprovides a soldering method and apparatus that, by properly selectingthe gas capable of discharge used for gas discharge, may also removeundesirable substances, for example, organic substances or oxides fromthe surface to be bonded in advance of applying the solder, thusimproving the wettability with the solder and effectively removing theorganic substances such as flux that remain after the soldering step iscomplete. In particular, this substantial improvement in thewettability, for example, enables soldering without the use of flux, or,for using a no-rinse flux which may have inherent low wettability.

To improve wettability, all types of gases, such as helium and nitrogen,may be effective. To obtain an ashing effect, compressed air, helium, ora mixed gas of nitrogen and oxygen may be effective. For etching, amixed gas, such as a mixture of helium or compressed air andfluorocarbon compounds (CF₄, C₂ F₆) or SF₆ may be effective.

Additionally, the apparatus and method of the invention includes stepsor device which may further increase the above-mentioned ashing effectby introducing water vapor or moisture to the atmospheric plasma whileexposing the surface of the material to be surface treated toatmospheric plasma also containing active species. This may beaccomplished by adding steam or directly supplying moisture to the gascapable of discharge prior to electrical discharge, or by supplyingmoisture directly to the surface of the substrate to be treated when itis exposed to the atmospheric plasma or reactive gas flow generated byelectrical discharge.

A good gas discharge may be generated in the method and apparatus of theinvention, for example, by using high-frequency voltage, at frequenciessuch as 13.56 MHz or around 10-30 kHz to generate electrical dischargein a gas capable of discharge.

The apparatus and method of the invention also provides using a brazingmaterial to bond two components together, and, more particularly,provides that the apparatus and method includes a surface-treater thatincludes a gas discharger device for generating electrical discharge ina gas capable of discharge at or about atmospheric pressure. A gassupply may supply a gas capable of discharge to the gas discharger forgenerating electrical discharge. A gas jetting port is provided forexposing the surface of at least one of the components to theatmospheric plasma containing active species, such as excited gasmolecules or ions, generated by the electrical discharge.

Furthermore, the method and apparatus of the invention includes asoldering device or step that, when using solder as a brazing material,may also remove such undesirable materials as oxide from the bondingsurface, improve wettability, and may effectively remove organicsubstances, such as flux, that may remain after soldering.

To generate the gas discharge at or about atmospheric pressure, it ispossible to use electrodes connected to a high-frequency power supply,and to directly expose the material to be treated to the atmosphericplasma thus generated, by generating the electrical discharge byapplying voltage from a power supply to the substrate or material to betreated which may be grounded. In another example, a gas flow ofatmospheric plasma containing active species, jets out from thedischarger and is directly applied to the substrate or material to betreated, thus exposing it to active species contained within theatmospheric plasma. In this case, damage to the substrate can beminimized by a device for trapping ions contained in the atmosphericplasma flow by, for example, providing a metal mesh on the gas jettingout port. In this way, low-cost, high-quality soldering can be achieved,especially when bonding components to a substrate.

The invention solves the above-mentioned problems associated withconventional technologies, and has as an object to provide a method anda device for soldering or bonding two components, that can easilyimprove the wettability of the surfaces to be bonded.

Another object of the invention is to provide a method and a device forsoldering using a low-corrosive, no-rinse flux, or without the use of aflux.

Yet another object of the invention, in cases involving the bonding ofelectronic components to a substrate by soldering, is to provide amethod and a device that improve the wettability of the substratewithout damaging it, and to make it possible to consistently obtain goodsoldering results, even for bonding processes involving fine wiringpatterns or small areas.

Still other objects and advantages of the invention will in part beobvious and will in part be apparent from the specification.

The invention accordingly comprises the several steps and the relationof one or more of such steps with respect to each of the others, and theapparatus combines features of construction, combinations of elementsand arrangement of parts which are adapted to affect such steps, all asexemplified in the following detailed disclosure, and the scope of theinvention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the invention, reference is had to thefollowing description taking in connection with the accompanyingdrawings, in which:

FIG. 1 is a schematic diagram showing a surface-treatment methodapparatus used in the bonding apparatus of the invention;

FIG. 2 is a schematic diagram showing another embodiment of asurface-treatment apparatus in accordance with the invention;

FIG. 3 is a schematic diagram showing still another embodiment of asurface-treatment and apparatus in accordance with the invention;

FIG. 4 is a cross-sectional view of the embodiment shown in FIG. 3 takenalong line IV--IV of FIG. 3;

FIG. 5(A) is an oblique cross-sectional of a nozzle used in thesurface-treatment apparatus of the embodiment shown in FIG. 2;

FIG. 5(B) is an oblique cross-sectional view of a different nozzle whichmay be used in the surface-treatment apparatus of the embodiment shownin FIG. 2;

FIG. 6 is a partial oblique cross-sectional view of an atmosphericplasma gun-type surface-treatment apparatus in accordance with theinvention;

FIG. 7(A) is a partial oblique cross-sectional view of asurface-treatment apparatus in which the electrical discharge generatingportion and the nozzle portion are separated;

FIG. 7(B) depicts another nozzle portion of the surface-treatmentapparatus of the embodiment shown in FIG. 7(A);

FIG. 8 is a schematic block diagram that depicts a surface-treatmentapparatus which is used to selectively treat certain selected portionsof the surface of a substrate;

FIGS. 9 through 14 are schematic block diagrams that depict thesoldering method and apparatus of the invention, and show workingexamples of different configurations for bonding components to asubstrate;

FIG. 15 is a flow diagram that shows a process that uses the bondingmethod and the device of the invention, in which both Substrate MountTechnology (SMT) and Chip on Board (COB) methods are employed for mixed,double-sided mounting of components on a substrate;

FIG. 16 is a flow diagram that shows a process in which the bondingmethod and apparatus of the invention are used for mounting componentson both sides of a substrate.

FIG. 17 is a schematic block diagram that shows a configuration of asurface-treatment apparatus, in which moisture is supplied through itsaddition to the gas capable of discharge prior to electrical discharge;and

FIGS. 18 and 19 are schematic block diagrams that show embodiments thatdiffer from that in FIG. 17, in which moisture is supplied to theatmospheric plasma containing active species generated by electricaldischarge in the discharger.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference is first made to FIG. 1 which depicts one configuration of asurface-treatment apparatus or surface-treater used in the bondingapparatus of the present invention. A long, thin, round, bar-shapedelectrical discharge electrode 2 coupled to a power supply 1 is heldelectrically suspended by an insulator 4 in the center of a metal cover3 which forms an approximately cylindrical shape and which is open atone end and is grounded. A substrate 5 is positioned perpendicularlywith respect to the length of electrode 2 at a specified distance fromelectrode 2 on a support table (not shown). The end of electrode 2protrudes past the end of metal cover 3, and a bonding surface 6 forsoldering electronic or other components faces the protruding end ofelectrode 2. The interior of the chamber formed by metal cover 3 isconnected to a gas supply 7 which supplies a gas capable of discharge.

The gas capable of discharge is supplied from gas supply 7 to theinterior of the chamber formed by metal cover 3, thereby replacing theambient atmosphere within the chamber and, by escaping out the open end,between electrode 2 and substrate 5. By applying high frequency voltagefrom power supply 1 to electrode 2, a gas discharge may be generated ator about atmospheric pressure between the protruding end of electrode 2and bonding surface 6 of substrate 5 which may be grounded, or if notgrounded, between the protruding end of electrode 2 and the supporttable, which in this case is grounded. In a discharge region 8, which islocated in the path of the electrical discharge between electrode 2 andbonding surface 6 of substrate 5 or the support table, atmosphericplasma generated by the above-mentioned electrical discharge causesvarious types of reactions, such as dissociation, ionization, andexcitation within the gas capable of discharge thus creating activespecies. Exposing bonding surface 6 of substrate 5 to the atmosphericplasma containing active species generated in the above-mentioned gasdischarge by these reactions, may improve bonding surface 6, by greatlyenhancing its hydrophilicity or wettability with respect to solder. Byusing the apparatus and method of the invention, good soldering resultsmay be obtained even when no flux is used, or when a no-rinse flux,ordinarily possessing low wettability, is used. In one working example,it is found that it is preferable to use high-frequency voltage of 13.56MHz or 20 KHz as the voltage to be applied to electrode 2, depending onthe type of gas capable of discharge used.

Any type of gas capable of discharge, for example, an inert gas such ashelium or argon, or nitrogen, compressed air, or oxygen and mixturesthereof, may be used as the gas capable of discharge supplied from gassupply 7 as long as it does not adversely effect the substrate. Forexample, if oxidation of the substrate is not desirable, it isrecommended that the gas capable of discharge includes gases other thanoxygen. Generally speaking, applying high-frequency voltage to an inertgas, such as helium or argon at or about atmospheric pressurefacilitates the generation of a stable and uniform electrical discharge,thus minimizing the damage to bonding surface 6 of substrate 5 exposedto the discharge. However, the costs of this process will be increasedbecause of the high price of the inert gas itself. To solve this costissue, it is preferable to replace the ambient atmosphere near electrode2 and substrate 5 with an inert gas that facilitates generation of astable electrical discharge, such as inert gases including helium orargon, just during the start of the electrical discharge. Then, once theelectrical discharge has taken place through application of highfrequency voltage, a switch can be made to another appropriate but lessexpensive gas capable of maintaining the stable discharge and selecteddepending on the surface treatment desired.

Surface treatment using the above-mentioned electrical discharge can beused for improving the wettability of bonding surface 6 of substrate 5,as well as for the preprocessing and postprocessing steps required for acomplete soldering process, as described below. For example, to removeany excess organic substances adhering to bonding surface 6 of substrate5 in advance, or to remove excess flux after soldering, a mixed gascontaining helium and oxygen may be supplied from gas supply 7. This gasgenerates atmospheric plasma containing active species, such as oxygenions and excited oxygen and helium gas molecules, which react with theaforementioned organic substances and combusts them, thus forming carbonmonoxide, carbon dioxide, and steam, which are then removed from bondingsurface 6. This reaction gas may be removed via a duct 9 provided nearsubstrate 5. A similar effect in removing organic substances, i.e., theashing effect, can be obtained by using compressed air or a mixed gascontaining nitrogen and oxygen as the gas capable of discharge.

A gas containing nitrogen, fluorine compounds (CF₄, C₂ F₆, SF₆, etc.),or an organic substance may also be used as the gas capable of dischargeto remove oxides from bonding surface 6 of substrate 5. In this case,the aforementioned oxides react with atmospheric plasma containingactive species, such as nitrogen ions and excited nitrogen gasmolecules, to form, for example, nitrogen oxides; or react with theactive species, such as fluorine ions and excited fluorine compound gasmolecules, to form fluorides; and may then be removed from bondingsurface 6 of substrate 5 by duct 9. When the gas capable of dischargecontains an organic substance, oxides on bonding surface 6 may reactwith the atmospheric plasma containing active species, such as organicsubstances, carbon, hydrogen ions, and excited organic substance gasmolecules which are generated through dissociation, ionization, andexcitation of the aforementioned organic substance by the electricaldischarge. In this way, hydroxy compounds, oxo compounds, carboxylicacids, carbon dioxide, and steam are formed, which may then be removedfrom bonding surface 6 of substrate 5 by duct 9.

It is also possible to coat the surface of substrate 5 with an organicsubstance instead of adding it to the gas capable of discharge. In thiscase, part of the organic substance coated on the substrate evaporatesfrom exposure to the electrical discharge and the atmospheric plasmagenerated and is then itself dissociated, ionized, and excited and isthen converted into active species such as activated organic substances,carbon, hydrogen ions, and excited organic gas molecules similar to whenthe organic substance is a component of the gas capable of discharge.Other parts of the organic substance are dissociated, ionized, andexcited by direct exposure to the active species of the atmosphericplasma generated by the electrical discharge and are then converted intoactive species of organic substances, carbon, hydrogen ions, and excitedorganic gas molecules as above.

These active organic species can offer the same effects as thoseobtained when an organic substance is directly added to the gas capableof discharge. Furthermore, unlike the chlorine compounds contained influxes, these active organic species do not remain on bonding surface 6of substrate 5.

Examples of gases capable of discharge for obtaining an etching effectfor removing oxides from bonding surface 6 of substrate 5 include a gascapable of discharge containing helium or compressed air and carbontetrafluoride. Naturally, if it is difficult to start electricaldischarge using this type of mixed gas, pure helium can be introduced atthe start of the electrical discharge for initially generating a stableelectrical discharge. Oxygen may also be substituted for compressed air.The inventor has confirmed that the maximum etching effect may beobtained when the volume of the fluorine compound, for example CF₄, as apercentage of helium is between 0.5 and 5%, and is ideally 1%; and thevolume of oxygen as a percentage of helium is between 0.5 and 5%, and isideally 1%, in the mixture of gases.

According to another example of the invention, only an inert gas isintroduced from gas supply 7 to generate electrical discharge. At thesame time, a second gas supply is used to supply reactive gases forexample, nitrogen, fluorine compounds, etc. depending on the surfacetreatment processing purpose desired, to discharge region 8 nearsubstrate 5. In this way, active species of the aforementioned reactivegas are generated by exposure to the electrical discharge and theatmospheric plasma generated, and the desired surface treatment isperformed.

As explained above, the bonding method and apparatus of the inventiongreatly improves the wettability of bonding surface 6 by improving itssurface properties before soldering. It also enables high-qualitysoldering by additionally removing oxides through etching, and easilyand thoroughly removes any flux remaining after soldering.

The bonding apparatus and method of this invention may also enhance theeffects of the reactive gas or atmospheric plasma containing activespecies by including water vapor or moisture to the gas capable ofdischarge or to the discharge region. In particular, the inventor hasconfirmed that etching speed and efficiency can be significantlyimproved. For example, the removal of a CuO film from a copper padsurface of a substrate took only about 20 seconds when a gas mixtureconsisting of helium and carbon tetrafluoride was used with the additionof moisture, such as steam; whereas the same operation had taken about20 minutes without the addition of moisture.

FIGS. 17 through 19 schematically show specific embodiments for addingmoisture to the reactive gas flow in order to enhance the effects of theelectrical discharge surface treatment of the bonding method andapparatus of the invention. In the embodiment shown in FIG. 17, a bypassis provided in the middle of a pipe 38, used for supplying the gascapable of discharge from gas supply 7 to a surface-treater 37 which maybe any of the surface-treaters described herein. Part of the gas capableof discharge is fed into a tank 40 after being regulated by a valve 39.Tank 40 contains water 41, ideally purified water, which may be heatedby a heater 42 and turned into steam. The gas introduced into tank 40returns to pipe 38 after absorbing and mixing with the steam, and thenmixes with the gas directly supplied from gas supply 7, before being fedto surface-treater 37.

The addition of moisture directly to the gas capable of discharge fed tosurface-treater 37 is beneficial because it eliminates the risk of dewcondensation from the moisture on the substrate (now shown). The amountof moisture may be adjusted by controlling valve 39, and by controllingthe temperature of water 41 in tank 40 through the use of the heater 42.

In another embodiment, shown in FIG. 18, an atomizer 43, is installed inthe middle of pipe 38 which connects gas supply 7 to the surface-treater(not shown). Water 41 is supplied to atomizer 43 from tank 40. Thisconfiguration enables the addition of moisture to the gas capable ofdischarge to be fed to the surface-treater. In this case, it is possibleto promote the atomization of water by supplying warm water to atomizer43 by installing a heater similar to that used in the embodiment shownin FIG. 17 in tank 40. It is also possible to install an air blower anda pipe separately from gas supply device 7 and pipe 38, in order todirectly force the water atomized by atomizer 43 into thesurface-treater, for example, the chamber formed by metal cover 3described in the embodiment shown in FIGS. 1 and 2, or directly to thearea near the bonding surface of the substrate and in the reactive gasflow.

In still another embodiment, shown in FIG. 19, steam is generated byheating water 41 in tank 40 with heater 42. The water vapor is thendirectly supplied, via a steam pipe 44, to a bonding surface (not shown)of substrate 5 and in the reactive gas flow where reactions withatmospheric plasma will then take place. In this case, the risk doesexist that dew condensation will occur on the bonding surface ofsubstrate 5, if substrate 5 is kept at a relatively low temperature. Ifit is considered that dew condensation may adversely affect substrate 5,it is possible to connect steam pipe 44 to the aforementionedsurface-treater or to the middle of pipe 38 as in either of theembodiments shown in FIGS. 17 and 18, so that moisture is added to theaforementioned gas capable of discharge before the electrical dischargeoccurs.

If the solder used on the bonding surface of substrate 5 for bondingcomponents has been oxidized, for example, by heating, the oxide can beremoved by applying a similar electrical discharge surface treatment tothe surface of the solder, thus ensuring good soldering results. It isalso recommended that electrical discharge surface treatment be appliedto individual components (not shown) that have been oxidized prior tobonding.

Furthermore, according to the method and apparatus of the invention,bonding surface 6 of substrate 5 or individual components (not shown),to which electrical discharge surface treatment is applied beforesoldering, need not consist of a metal, for example copper. The inventorhas confirmed that the invention also facilities the removal of oxidesfrom materials such as glass or Indium Tin Oxide (ITO), again resultingin high-quality soldering.

For example, it was confirmed that excellent wettability and adhesion ofsolder to glass materials can be achieved, without the use of any flux,by using nitrogen alone as the gas capable of discharge. Therefore, itbecomes possible to directly assemble components, for example, IC chipsto a glass surface of a liquid crystal panel, without the necessity offorming a precoat on the surface in advance and then bonding thecomponents via a TAB substrate.

Naturally, metal cover 3 is not an absolute requirement for electricaldischarge to occur. Furthermore, cover 3 can be made of ceramic materialinstead of metal.

FIG. 2 shows another embodiment of a surface-treater of the invention.In this example, a grounded electrode corresponding to power supplyelectrode 2 has been separately installed, instead of using substrate 5as the grounded electrode, as is the case of the embodiment shown inFIG. 1. That is, the bottom of metal cover 3 is extended to a positionnear the tip of electrode 2, so that electrode 2, rather thanprotruding, is completely encased inside metal cover 3, and thisextended portion of metal cover 3 is used as the grounded electrode 10for generating electrical discharge. Substrate 5 is then positioned on aholder 12, which may possess either a heating or cooling function (notshown), adjacent the opening 11 formed by grounded electrode 10 on metalcover 3. Furthermore, cooling water may be circulated from a coolingdevice 13 via pipes 14 and 15 to electrode 2, to cool electrode 2 andprevent it from overheating as a result of electrical dischargetreatment over an extended period of time. Additionally, a metal mesh 16may be installed at the opening of metal cover 3.

As in the embodiment shown in FIG. 1, the gas capable of discharge issupplied from gas supply 7, and the gas replaces the ambient atmosphereinside metal cover 3. When high-frequency voltage is applied from powersupply 1 to electrode 2, gas discharge occurs between the tip ofelectrode 2 and grounded electrode 10. Since the aforementioned gascapable of discharge is continuously being supplied from gas supply 7,when the gas passes through discharge region 8, part of this gas isconverted to atmospheric plasma containing active species, such as ionsand excited gas molecules, and jets out as a reactive gas flow 17,through bottom opening 11 of metal cover 3. The property of bondingsurface 6 of substrate 5 is modified through ashing or etching,depending on the type of gas supplied from gas supply 7, and thus, bythe aforementioned atmospheric plasma containing active speciescontained in reactive gas flow 17.

In another example, as in the embodiment shown in FIG. 1, only an inertgas, for example helium or argon, is introduced from gas supply device 7for initially generating stable electrical discharge, while a second gassupply (not shown) is used to supply a reactive gas, such as nitrogen ora fluorine compound, depending on the processing purpose, to thevicinity of substrate 5. Reactive gas active species are generatedthrough the energy exchange between, for example, helium radicals thatare generated by the aforementioned electrical discharge and that jetout through bottom opening 11, and the aforementioned reactive gas.Reactive gas active species are then used for the desired surfacetreatment.

Because this working example uses a configuration in which bondingsurface 6 of substrate 5 is not exposed directly to electricaldischarge, and is instead exposed to reactive gas flow 17, theprocessing effectiveness becomes slightly less than in the embodimentshown in FIG. 1, due to the short life spans of the ions. Naturally,this trend becomes more pronounced as the distance between substrate 5and bottom opening 11 of metal cover 3 increases.

On the other hand, however, if the ions have adverse effects onsubstrate 5 metal mesh 16 installed at bottom opening 11 may be used toremove the ions from reactive gas flow 17, by trapping and neutralizingthe ions contained in reactive gas flow 17. Consequently, bondingsurface 6 of substrate 5 is treated by atmospheric plasma that does notcontain ions.

Depending on the conditions, substrate 5 may be heated to temperaturesabove 200° C. by the electrical discharge itself or by the heat radiatedfrom electrode 2. Therefore, if it is necessary to protect substrate 5against heat, holder 12 can be used to cool substrate 5 during theprocessing. On the other hand, if it is not necessary to protectsubstrate 5 against heat, it should be actively heated in order to speedthe reaction rate. Because the chemical reaction is a type of reductionreaction, heating usually accelerates the reactions. Furthermore,surface treatment and soldering can be simultaneously achieved byapplying the electrical discharge surface treatment of the inventionwhile heating substrate 5, on which the solder and components have beenplaced, to a temperature above the melting point of the solder.

A light source, such as a halogen lamp (not shown), may also be used asa heating device. This method minimizes time loss by quickly heatingbonding surface 6, and also makes it easy to heat substrate 5 even if ithas a complicated shape with severe irregularities. It is also possibleto use a short-wave light (not shown), for example, ultraviolet light,from a light source. This method enhances, for example, rinsingperformance, because the ultraviolet light severs the chemical bonds oforganic substances facilitating ashing, in addition to providing theaforementioned heating effect.

As a supplementary method, a blower can be used to blast the atmosphericplasma or reactive gas flow 17 against substrate 5. This allows removalof organic substances from bonding surface 6, while the aforementionedgas can additionally blast off the inorganic impurities that are coveredby, or adhered to, these organic substances. These effects can also beachieved by increasing the flow of the gas capable of discharge suppliedto the chamber formed from metal cover 3, rather than installing aseparate blower. Furthermore, the gas flow from the aforementionedblower can also be used as either a cooling or heating means, byseparately controlling its temperature. Depending on the conditions, ifthere is a risk of dew adhesion to electrode 2, it is possible to use anappropriate heater (not shown) to heat the area around electrode 2 andmetal cover 3.

FIGS. 3 and 4 show still another embodiment of the invention, which is amodification of the embodiment shown in FIG. 2. As in the priorembodiments discussed above, a long, thin, bar-shaped electrode 2 forelectrical discharge generation is held within metal cover 3 byinsulator 4.

Metal cover 3 is shaped like a long box with a roughly square crosssection, and its length slightly exceeds that of electrode 2. It ispositioned so that its diagonal lines are in the vertical and horizontaldirections. Furthermore, the bottom corner of the aforementioned squareis cut out over the entire length at a specified width, thus forminglong opening 11 which allows reactive gas flow 17 to jet out of metalcover 3. The edges of cover 3 form grounded electrode 10 and opening 11along length of cover 3, similar to the embodiment shown in FIG. 2.Naturally, it is possible to design the structure so that electricaldischarge is generated between electrode 2 and grounded substrate 5, asin the embodiment shown in FIG. 1, by making electrode 2 protrude out ofmetal cover 3 by, for example, increasing the width of opening 11 ofmetal cover 3, or by removing metal cover 3 altogether.

Similar to the above embodiments, by supplying a gas capable ofdischarge from gas supply 7, the ambient atmosphere in the vicinity ofelectrode 2, and substrate 5 is replaced by the gas capable ofdischarge. Then, when high-frequency voltage is applied from powersupply 1 to electrode 2, gas discharge occurs along and between theentire length of electrode 2 and grounded electrode 10 of metal cover 3.The atmospheric plasma containing active species of the aforementionedgas capable of discharge generated by the electrical discharge, jets outthrough opening 11 over substantially all its entire length as reactivegas flow 17. In this way, bonding surface 6 of substrate 5 is exposed tothe aforementioned atmospheric plasma containing active species linearlyalong the length of electrode 2. During this exposure, by moving eitheror both the aforementioned surface-treater or substrate 5 width-wiserelative to electrode 2, or in some cases also lengthwise, it becomespossible to surface treat the entire bonding surface 6 of substrate 5,even if it is large.

Drawings 5(A) and 5(B) show modified examples of the structure ofelectrode 2 and metal cover 3 in the embodiments described above. Inboth of these examples, electrode 2 for electrical discharge generationis enclosed inside metal cover 3 that forms an internal chamber 18 withan inverted T shape cross section. Furthermore, numerous gas jet ports20 are spaced on surface 19 of metal cover 3, in both the lengthwise andwidthwise directions.

In the example shown in FIG. 5(A), electrical discharge occurs onlybetween electrode 2 and the center area of surface 19 of metal cover 3positioned immediately adjacent electrode 2, because electrode 2 isshaped like a plate with an I-shaped cross section and extends along thelength of metal cover 3. Consequently, reactive gas flow 17 jets outmostly through those jetting ports 20 located near the center. Incontrast, in the example in FIG. 5(B), electrode 2 possesses an invertedT shape cross section that matches the shape of internal chamber 18 ofmetal cover 3. Consequently, electrical discharge occurs between thearea 21, which extends in a flange-like fashion along the width ofelectrode 2, and corresponding surface 19 of metal cover 3, over nearlyits entire surface. Therefore, reactive gas flow 17 jets out throughalmost all of jetting ports 20. As can be seen, the locations forgenerating electrical discharge, the number of locations, and the gasjetting ports, etc. can be adjusted freely and appropriately based onthe usage conditions and the material to be treated. Furthermore,because this type of configuration can increase the size of two surfacetreatment area, it is possible to simultaneously process a large numberof substrate at once.

Additionally, the structures of metal cover 3 and electrode 2 shown inFIGS. 5(A) and 5(B) can also be applied to the structures shown in theembodiments of FIGS. 1 and 2.

FIG. 6 shows an overview of a so-called "gun-type" surface-treater 22that is used for locally applying surface treatment ofatmospheric-plasma generated by electrical discharge to materials to beprocessed, such as a substrate, as required on the shop floor or localmanufacturing site where soldering is performed. Surface-treater 22possesses a gun type structure, which may be held by an operator asneeded. A discharge generating portion 24 is held within a cylindricalnozzle 23 that possesses an opening at its tip. The basic structure ofdischarge generating portion 24 is similar to the structure of theembodiment shown in FIG. 2 and is connected to a gas supply (not shown)and a power supply (not shown), as in the above-mentioned embodiment. Inthis structure, a reactive gas flow of atmospheric plasma containingactive species generated by the electrical discharge is guided by tipopening 25 of nozzle 23 to jet out toward bonding surface 6 of substrate5, from the open area of discharge generating portion 24.

FIG. 7(A) shows a surface-treater 29, in which the electrical dischargegenerating portion 26 and the nozzle 27a, used for jetting out reactivegas flow 17, are provided separately and connected via a flexible tube28. The electrical discharge generating portion 26 is housed inside amain unit 30 which can be either a fixed type that integrates a powersupply and a gas supply etc. (not shown in drawing), or a mobile type.Reactive gas flow 17 of atmospheric plasma generated by electricaldischarge is supplied to nozzle 27a via flexible tube 28 and is jettedout toward substrate 5 through nozzle 27a. In order to effectivelydeliver the atmospheric plasma containing active species to substrate 5,the length of flexible tube 28 should be a maximum of about 5 m, andideally around 2 m. Having nozzle 27a as a separate unit improvesproductivity, and also allows the processing capacity of surface-treater29 to be increased as needed.

The nozzle 27a installed at the tip of flexible tube 28 may beremovable. FIG. 7(B) shows a nozzle 27b of a different embodiment whichis removable and replaceable on tube 28. While nozzle 27a in FIG. 7(A)consists of a relatively large disk which is capable of processing alarge area at one time, the nozzle area 27b in Drawing 7B is rectangularin shape and is suitable for processing relatively small and fine areas.This ability to change nozzles enables surface-treater 29 to adapt tochanges in the material to be surface treated and to usage conditions,thus enhancing operational flexibility and overall productivity.

Use of the surface-treaters of the bonding method and apparatus of theinvention makes it possible to selectively surface treat bonding surface6 of substrate 5 to be treated by changing the shape of thehigh-frequency electrode used for generating electrical discharge,rather than employing a masking method. For example, as shown in FIG. 8,when many electronic or other components 45 have been mounted on bothsides of substrate 5, and when it is necessary to solder a new componentonto bonding surface 6, the tip shape of electrode 2 can be changed tomatch the position, shape, and range of the surfaces to be soldered. Forexample, if the aforementioned new component is a square-shaped IC withleads on all four sides, a hollow square shape can be used for theelectrode tip. Although the shape accuracy, i.e., the ratio between theshape of the electrode and the shape of the surface actually treated,will vary depending on the voltage applied to the electrode, thedistance between bonding surface 6, and the flow rate of the gas used,etc., the actual surface treatment has been performed by the inventorswith an accuracy of 2 to 3 mm. Furthermore, if substrate 5 to be surfacetreated is not an insulating material, such as a metal or glasssubstrate, the accuracy can be improved by placing a grounded electrode(not shown) below bonding surface 6 of substrate 5 and matching theshape of this grounded electrode to the shape of the area to be surfacetreated. In this way, it is possible to improve wettability, or toperform ashing, or etching, etc., while protecting other components onsubstrate 5 against the effects of the electrical discharge or reactivegas flow 17.

So far, the methods and apparatus of surface treating the surface of asubstrate to be bonded have been explained. By integrating thesesurface-treaters with soldering machines, it is possible to producebetter soldering results, and to improve overall productivity throughmore efficient soldering operations and automation. Furthermore, thefact that excellent soldering results can uniformly and efficiently beobtained, even for small and find areas, the apparatus and method of theinvention offers the benefit of a high degree of freedom in designingcircuit boards and wiring patterns. Soldering methods and apparatusesinvolving surface treatment by the surface-treaters described above areexplained below in detail.

FIG. 9 shows a block diagram of the configuration of an example of asubstrate soldering and bonding apparatus of the invention. A solderpaste printer 32, a mounter 33, and a reflow oven 34 are positioned inseries on the downstream side of surface-treater 31. First, aftersurface treatment is applied to the substrate by surface-treater 31,solder paste printer 32 prints a pattern of paste solder on the surfacetreated substrate. Next, mounter 33 mounts components, and finally,soldering is completed through heating using reflow oven 34. Applicationof surface treatment to the substrate by surface-treater 31 at thestart, as described above, improves the wettability of the substrate tosolder paste. Thus, excellent soldering results can be obtained even ifthe amount of flux contained in the solder paste is small or nonexistentas in non-flux solders with inherently bad wettability.

Based on the example of the embodiment shown in FIG. 9, experiments wereconducted using glass substrate with ITO wiring, and glass epoxysubstrate with copper wiring. The results are shown in Table 1. Thefollowing gases capable of discharge were used for surface-treater 31:helium as an inert gas; oxygen, air, and mixture of air and an inertrare gas as oxidizing gases; and propane, and a mixture of propane andan inert gas as reducing gases. Additionally, an experiment was alsoconducted in which an n-hexane coating was applied as an organicsubstance on the substrate prior to surface treatment by surface treater31. In these experiments, a 13.56 MHz high-frequency power supply wasused for generating electrical discharge at atmospheric pressure.

                  TABLE 1                                                         ______________________________________                                                  Gas type     Power used                                                                              Results                                                (Electrical  (13.56    Glass  ITO                                     Pretreatment Discharge) MHz) epoxy Glass                                    ______________________________________                                        None      He            30 W     B      B                                        C3H8 100 W A A                                                                He + C3H8  30 W A A                                                           He + Air + C3H8  30 W A A                                                     Air + C3H8 100 W A A                                                          O2  30 W C C                                                                  Air 100 W C C                                                                 He + Air  30 W C C                                                           n-hexane coating He  30 W C C                                                  C3H8 100 W A A                                                                He + C3H8  30 W A A                                                           He + Air + C3H8  30 W A A                                                     Air + C3H8  30 W A A                                                          O2  30 W A A                                                                  Air 100 W A A                                                                 He + Air  30 W A A                                                         ______________________________________                                         The results were judged according to the following three categories:          A: Good solderability                                                         B: No change after treatment                                                  C: Solderability deteriorated after treatment                            

The above results indicate that solderability improved in both glasssubstrate with ITO wiring and glass epoxy substrate with copper wiring,when a gas containing a reducing gas which contained an organicsubstance was used, and/or when the substrate was coated with an organicsubstance for providing the reducing gas before surface treatment.Similar results were also obtained when 400 KHz and 10 KHz powersupplies were used. In other words, even if no reducing gas is suppliedfrom outside, solderability can be improved as long as a source ofreducing gas exists on the surface to be treated. Furthermore,electrical discharge selectively occurs between the electrode and theareas of the substrate where conductive materials are present.Therefore, in the case of the aforementioned glass substrate, electricaldischarge selectively occurs between the electrode and the ITO wiringarea, and between the electrode and the copper wiring area in the caseof the epoxy substrate, resulting in surface treatment in both cases ofjust the conductive wire elements. Consequently, since surface treatmentdoes not occur in areas other than the above-mentioned wiring areas, itis not necessary to protect these other areas against damage, using, forexample, masks.

FIGS. 10 through 14 show other examples of the soldering apparatus ofthis invention. In the example shown in FIG. 10, surface-treater 31 ispositioned between paste solder printer 32 and mounter 33. After pastesolder is printed on the substrate by paste solder printer 32, surfacetreatment is applied to the substrate by surface-treater 31. Next, thecomponents are mounted by mounter 33, and finally, soldering iscompleted through heating using reflow oven 34.

In the example shown in FIG. 11, surface-treater 31 is positionedbetween mounter 33 and reflow oven 34. After paste solder is printed onthe substrate by paste solder printer 32, the components are mounted bymounter 33. Next, surface treatment is applied to the substrate bysurface-treater 31, and finally, soldering is completed by reflow oven34.

In the example shown in FIG. 12, surface-treater 31 and reflow oven 34are integrated as one unit. After paste solder is printed on thesubstrate by paste solder printer 32, the components are mounted by themounter 33. Next, surface treatment is applied to the substrate by thesurface-treater 31, and the surface treatment continues during heatingwith reflow oven 34, to complete soldering.

The example shown in FIG. 13 is a device for wave-soldering componentsonto a substrate, and includes an inserter 35 and a wave-solderingdevice 36 which are positioned on the downstream side of surface-treater31. After surface treatment is applied to the substrate bysurface-treater 31, the components are inserted by inserter 35, and thensoldering is completed using wave-soldering device 36. This method makessoldering possible even if the amount of flux is very small ornonexistent.

FIG. 14 shows a modified version of the example in FIG. 13.Surface-treater 31 is positioned between inserter 35 and wave-solderingdevice 36. In this configuration, after the components are mounted byinserter 35, surface treatment is applied to the substrate bysurface-treater 31, and then soldering is completed using wave-solderingdevice 36. This method also makes soldering possible even if the amountof flux is very small or nonexistent.

Next, an explanation is provided for a method of assembling mixed typesof electronic components onto a substrate by using the bonding apparatusand method of the invention, along with both SMT (Surface MountTechnology) and COB (Chip On Board) technology. Usually in SMT mounting,a reflow oven is used for heating and soldering after the components aremounted. Therefore, the conventional practice is to first assemble barechips and components using a COB mounting method, followed by SMTmounting, in order to prevent splashing flux, etc. from contaminatingthe bonding surface of the substrate, or to prevent the formation ofoxide films. In contrast, the invention makes it possible to perform SMTmounting first, followed by COB mounting.

As shown in the flow chart of FIG. 15, paste solder is first printed onspecific locations on a substrate surface, and then, after mounting allsurface-mount components, except for the bare chips to be COB-assembled,a reflow oven is used for heating and soldering. Next, the flux adheredto the pad surfaces to be used for wire bonding, and the oxide filmsformed during heating steps are easily removed by using thesurface-treaters of the invention to apply surface treatment to thesurface of the aforementioned substrate. Afterwards, bare chips areglued to their mounting locations on the substrate, bonded through wirebonding, and their surface is sealed with a resin for completion of achip package. Furthermore, the invention makes it possible to treat onlythe selected locations on the substrate with accuracy of about 2 to 3mm; and in particular, highly selective and effective treatment can beapplied to only the metal pads, between which electrical discharge tendsto occur due to their conductive nature.

When the wet method described earlier is used for rinsing and removingorganic substances, there is a risk that the rinsing agent willadversely affect the electronic components on the substrate. On theother hand, ashing at low pressure has the problem of the additionaltime required in bringing the substrate to a low pressure atmosphere andmay be ineffective in treating highly irregular areas or removing highmolecular weight organic substance. If COB mounting is performed firstas in conventional methods, surface-mount components cannot bepositioned near the bare chips that have been resin-molded, because ofthe resulting difficulty in applying paste solder to those areascontaining resin. Furthermore, the paste solder printing mask used forSMT mounting must be equipped with escape holes for the resin mold ofthe COB mounting, thus resulting in higher mask production cost.Additionally, if the substrate is thin, it tends to warp after COBmounting, making subsequent SMT mounting difficult. The bonding methodand apparatus of the invention, on the other hand, solves theseproblems, in that it produces higher-quality soldering, increases thedegree of freedom in designing circuit boards, enables the soldering ofsmaller-size substrate, and facilitates higher-density assemblies.

FIG. 16 shows a flow diagram of a process in which components aremounted on both sides of a substrate through soldering. First, a pastesolder printer is used to print paste solder on one side of thesubstrate, then after the components are placed on the substrate, theyare passed through a reflow oven to complete the soldering on this side.Next, the substrate is turned over so that the other side faces up,surface treatment using atmospheric plasma generated by electricaldischarge by the surface-treaters of the invention is applied. Then, asin normal assembly operations, the paste solder is printed, thecomponents are placed, and finally the mounting of components on bothsides of the aforementioned substrate is completed by heating thesubstrate and components in a reflow oven.

In this type of substrate with double-sided mounting, the heat treatmentused for soldering on one side oxidizes the copper pads, electrodes,etc. on the other side. However, by using atmospheric plasma generatedby electrical discharge as a treatment to remove the oxide film,conductivity and wettability can be recovered to a level equivalent tothat before heat-induced oxidation, and thus good soldering may beachieved on the second side. Additionally, because the electricaldischarge treatment of the invention can be applied to either the top orbottom side of a substrate, regardless of its orientation, it is alsopossible to apply it to the remaining side before inverting thesubstrate, after reflow and soldering are completed on the other side.Furthermore, even better soldering results can be achieved by applyingelectrical discharge treatment to one of the sides before paste solderis printed on it, and to the components to be mounted.

The invention has been explained above in detail with references toappropriate working examples, but the invention can be implemented inmany other ways by making various changes or modifications to the aboveexamples within its technical scope. For example, the electrode forgenerating electrical discharge is not limited to the bar and plateshapes, and can be shaped as a sphere or a non-spherical curved shape,etc. These shapes enable the generation of the type of electricaldischarge that best suits the processing conditions.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efficiently attained, and,since certain changes may be made in carrying out the above process andin the constructions set forth without departing from the spirit andscope of the invention, it is intended that all matter contained in theabove description and shown in the accompanying figures shall beinterpreted illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall there between.

We claim:
 1. A method of bonding components together using a brazingmaterial., comprising the steps of:providing a gas capable of discharge;generating discharge in said gas capable of discharge at or aboutatmospheric pressure thereby creating an atmospheric plasma havingactive species; exposing at least a portion of at least a firstcomponent to said atmospheric plasma having active species therebysurface treating said portion; and bonding said first component to asecond component using a brazing material.
 2. The method of claim 1wherein the gas capable of discharge contains at least an organicsubstance.
 3. The method of claim 1 further comprising the stepof:coating at least one of the portion of said first component and saidsecond component with an organic substance prior to exposing said coatedportion to the atmospheric plasma.
 4. The method of claim 3 wherein thesurface of one of said first and second components is selectivelyexposed to said active species.
 5. The method of claim 3 wherein the gascapable of discharge contains at least helium.
 6. The method of claim 3wherein the gas capable of discharge contains at least compressed air.7. The method of claim 3 wherein the gas capable of discharge containsat least nitrogen.
 8. The method of claim 3 further comprising the stepof:providing moisture proximate the coated portion while exposing thecoated portion to the atmospheric plasma.
 9. The method of claim 3wherein the coated portion is directly exposed to the discharge.
 10. Themethod of claim 3 further comprising the step of:providing a continuoussupply of gas capable of discharge thereby forming a gas flow;generating a discharge in said gas flow thereby creating a reactive gasflow of the atmospheric plasma; and directly exposing the coated portionto said reactive gas flow.
 11. The method of claim 3 wherein the brazingmaterial is solder.
 12. The method of claim 1 wherein exposing theportion to the atmospheric plasma is performed at least one of before,during, and after said bonding step.
 13. The method of claim 1 whereinthe surface of one of said first and second components is selectivelyexposed to said active species.
 14. The method of claim 13 wherein thegas capable of discharge contains at least helium.
 15. The method ofclaim 13 wherein the gas capable of discharge contains at leastcompressed air.
 16. The method of claim 13 wherein the gas capable ofdischarge contains at least nitrogen.
 17. The method of claim 13 whereinthe gas capable of discharge contains at least one of helium andnitrogen, and oxygen.
 18. The method of claim 13 wherein the gas capableof discharge contains at least one of helium and compressed air, and afluorine compound.
 19. The method of claim 13 further comprising thestep of:providing moisture proximate the portion while exposing theportion to the atmospheric plasma.
 20. The method of claim 13 whereinthe portion is directly exposed to the discharge.
 21. The method ofclaim 13 further comprising the step of:providing a continuous supply ofgas capable of discharge thereby forming a gas flow; generating adischarge in said gas flow thereby creating a reactive gas flow of theatmospheric plasma; and directly exposing the coated portion to saidreactive gas flow.
 22. The method of claim 13 wherein the brazingmaterial is solder.
 23. The method of claim 1 wherein the gas capable ofdischarge contains at least helium.
 24. The method of claim 1 whereinthe gas capable of discharge contains at least compressed air.
 25. Themethod of claim 1 wherein the gas capable of discharge contains at leastnitrogen.
 26. The method of claim 1 wherein the gas capable of dischargecontains at least one of helium and nitrogen, and oxygen.
 27. The methodof claim 1 wherein the gas capable of discharge contains at least one ofhelium and compressed air, and a fluorine compound.
 28. The method ofclaim 1 further comprising the step of:providing moisture proximate theportion while exposing the portion to the atmospheric plasma.
 29. Themethod of claim 28 wherein the portion is directly exposed to thedischarge.
 30. The method of claim 28 further comprising the stepof:providing a continuous supply of gas capable of discharge therebyforming a gas flow; generating a discharge in said gas flow therebycreating a reactive gas flow of the atmospheric plasma; and directlyexposing the coated portion to said reactive gas flow.
 31. The method ofclaim 28 wherein the brazing material is solder.
 32. The method of claim1 wherein the portion is directly exposed to the discharge.
 33. Themethod of claim 1 further comprising the step of:providing a continuoussupply of gas capable of discharge thereby forming a gas flow;generating a discharge in said gas flow thereby creating a reactive gasflow of the atmospheric plasma; and directly exposing the portion tosaid reactive gas flow.
 34. The method of claim 1 wherein high-frequencyvoltage is used for generating discharge.
 35. The method of claim 1wherein the brazing material is solder.
 36. The method of claim 35wherein no flux is used.
 37. The method of claim 35 wherein a no-rinseflux is used.
 38. The method of claim 35 wherein one of said first andsecond components is a glass substrate; andwherein the gas capable ofdischarge is nitrogen.
 39. A method of bonding components together usinga brazing material, comprising the steps of:providing a first component,a second component and a brazing material; providing a gas capable ofdischarge; generating plasma discharge in said gas capable of dischargeat or about atmospheric pressure thereby creating active species;coating at least a portion of one of said first component and saidsecond component with said brazing material exposing at least a portionof one of said first component and said second component to said activespecies thereby surface treating said portion; and bonding said firstcomponent to said second component using said brazing material.
 40. Themethod of claim 39 wherein the gas capable of discharge contains atleast an organic substance.
 41. The method of claim 39 furthercomprising:a coater for coating an organic substance on the portionprior to being exposed to the atmospheric plasma.
 42. The method ofclaim 41 wherein the surface-treater further includes:a port shaped forselecting the portion from the entirety of a surface of the firstcomponent for exposure to the atmospheric plasma, thereby leaving areasof said surface not exposed to the atmospheric plasma.
 43. The method ofclaim 41 wherein the coated portion is grounded, and wherein thedischarger further includes:an electrode coupleable to a power supply;and wherein the discharge is generated between said electrode and saidgrounded coated portion thereby directly exposing the coated portion tothe discharge.
 44. The method of claim 41 wherein the discharger furtherincludes:a continuous supply of gas capable of discharge forming a gasflow, a first electrode coupleable to a power supply, and a secondelectrode that is grounded; and wherein discharge is generated in saidgas flow thereby creating a reactive gas flow of the atmospheric plasma,and wherein the coated portion is directly exposed to said reactive gasflow.
 45. The method of claim 44 wherein the discharger furtherincludes:a tube for directing the reactive gas flow, said tube having anozzle for permitting the reactive gas flow to escape; and wherein theportion is directly exposed to the reactive gas flow escaping thedischarger through said nozzle.
 46. The method of claim 41 wherein thegas capable of discharge contains at least helium.
 47. The method ofclaim 41 wherein the gas capable of discharge contains at leastcompressed air.
 48. The method of claim 41 wherein the gas capable ofdischarge contains at least nitrogen.
 49. The method of claim 41 whereinmoisture is added when exposing the coated portion to the atmosphericplasma.
 50. The method of claim 41 wherein the brazing material is asolder.
 51. The method of claim 39 wherein the portion is exposed to theatmospheric plasma at least one of before, during, and after bonding thefirst component to a second component.
 52. The method of claim 39wherein the surface-treater further includes:a port shaped for selectingthe portion from the entirety of a surface of the first component forexposure to the atmospheric plasma, thereby leaving areas of saidsurface not exposed to the atmospheric plasma.
 53. The method of claim52 wherein the portion is grounded, and wherein the discharger furtherincludes:an electrode coupleable to a power supply; and wherein thedischarge is generated between said electrode and said grounded portionthereby directly exposing the portion to the discharge.
 54. The methodof claim 52 wherein the discharger further includes:a continuous supplyof gas capable of discharge forming a gas flow, a first electrodecoupleable to a power supply, and a second electrode that is grounded;and wherein discharge is generated in said gas flow thereby creating areactive gas flow of the atmospheric plasma, and wherein the portion isdirectly exposed to said reactive gas flow.
 55. The method of claim 54wherein the discharger further includes:a tube for directing thereactive gas flow, said tube having a nozzle for permitting the reactivegas flow to escape; and wherein the portion is directly exposed to thereactive gas flow escaping the discharger through said nozzle.
 56. Themethod of claim 52 wherein the brazing material is a solder.
 57. Themethod of claim 39 wherein the portion is grounded, and wherein thedischarger further includes:an electrode coupleable to a power supply;and wherein the discharge is generated between said electrode and saidgrounded portion thereby directly exposing the portion to the discharge.58. The method of claim 57 wherein said electrode coupleable to a powersupply having a high-frequency power source.
 59. The method of claim 39wherein the discharger further includes:a continuous supply of gascapable of discharge forming a gas flow, a first electrode coupleable toa power supply, and a second electrode that is grounded; and whereindischarge is generated in said gas flow thereby creating a reactive gasflow of the atmospheric plasma, and wherein the portion is directlyexposed to said reactive gas flow.
 60. The method of claim 55 whereinthe discharger further includes:a tube for directing the reactive gasflow, said tube having a nozzle for permitting the reactive gas flow toescape; and wherein the portion is directly exposed to the reactive gasflow escaping the discharger through said nozzle.
 61. The method ofclaim 60 wherein the gas capable of discharge contains at least helium.62. The method of claim 60 wherein the gas capable of discharge containsat least compressed air.
 63. The method of claim 60 wherein the gascapable of discharge contains at least nitrogen.
 64. The method of claim60 wherein moisture is added when exposing the portion to theatmospheric plasma.
 65. The method of claim 60 wherein the brazingmaterial is a solder.
 66. The method of claim 55 wherein the gas capableof discharge contains at least helium.
 67. The method of claim 55wherein the gas capable of discharge contains at least compressed air.68. The method of claim 55 wherein the gas capable of discharge containsat least nitrogen.
 69. The method of claim 59 wherein moisture is addedwhen exposing the portion to the atmospheric plasma.
 70. The method ofclaim 59 wherein the brazing material is a solder.
 71. The method ofclaim 39 wherein the gas capable of discharge contains at least helium.72. The method of claim 39 wherein the gas capable of discharge containsat least compressed air.
 73. The method of claim 39 wherein the gascapable of discharge contains at least nitrogen.
 74. The method of claim39 wherein the gas capable of discharge contains at least one of heliumand nitrogen, and oxygen.
 75. The method of claim 39 wherein the gascapable of discharge contains at least one of helium and compressed air,and a fluorine compound.
 76. The method of claim 39 wherein moisture isadded when exposing the portion of the atmospheric plasma.
 77. Themethod of claim 76 wherein the brazing material is a solder.
 78. Themethod of claim 39 wherein the brazing material is a solder.